Canada and other western powers condemned the use of force by Myanmar's military junta in suppressing this week's peaceful protests by Buddhist monks, students and other pro-democracy dissidents, but China and Russia used the shadow of the veto they hold in the United Nations Security Council to blunt the world body's response.

() Amid fears the junta's crackdown on pro-democracy protesters will increase in intensity, the United States and the 27-member European Union asked the Security Council to consider imposing sanctions on the regime.

The U.S.-EU communique also called for the council to demand the government open a dialogue with jailed opposition leader Aung San Suu Kyi and ethnic minorities in the country.

() But China and Russia, which have friendly relations with Myanmar's military rulers, said the council is mandated to deal only with matters threatening international peace and security.

The debate at the UN came as military leaders in Myanmar cracked down on mass demonstrations that began as a protest against rising fuel prices but have expanded to express the long-felt dissatisfaction with the rulers of one of Asia's poorest nations.

() Meanwhile, in the absence of assertive action at the UN, western powers were left announcing unilateral responses.

President George W. Bush said the United States would tighten economic sanctions on junta leaders and their financial backers, and expand a visa ban "on those most responsible for the egregious violations of human rights."

() Foreign Minister Maxime Bernier, at the UN for the annual General Assembly debate, said Canada demands an immediate end to the junta's attacks. "Canada condemns the use of deadly force by the military and police against the monks and other protesters in Burma who were expressing their right to peaceful dissent," he said, avoiding the junta's name for the country.

() In an interview Wednesday, a senior official with Burma's government-in-exile argued that a principle the Canadian government under the previous Liberal administration promoted, referred to a "responsibility to protect," remains grounds for Security Council action.

"This was Canada's brainchild and we're asking the Canadian government to help us organize an inter-governmental lobby to press the need for responsibility to protect at the Security Council," said Thaung Htun, representative in UN matters for the Union of Burma.

The Security Council last year endorsed the principle, which says international intervention is justified to protect civilians whose government can't or won't do so.

British Prime Minister George Brown said there would be "no impunity" for human rights violators in Myanmar.

Last January, however, China and Russia used their vetoes to block a resolution demanding that Myanmar release political prisoners and end sexual violence by the military.

() The unrest that has escalated into the largest protests seen in Myanmar in 20 years began last month when the junta dramatically raised the price of fuel overnight, deepening the misery in this already impoverished country. The initial protests -- rare in a nation where the military quickly crushes any show of dissent -- began with only a handful of marching demonstrators. ()